The possibility of Donald Trump returning to the White House has resuscitated debate about the reliability of the US alliance, including the nuclear protection Washington extends to Australia and other allies.

Whoever wins the presidential election in November, Australia needs to deepen its contribution to extended nuclear deterrence, as the US nuclear umbrella is formally known, to keep Washington engaged. As ASPI senior fellow Rod Lyon put it, assurance is a two-way street.

One way to demonstrate that Canberra has real skin in the deterrence game is to host more US nuclear forces.

Australia is yet to follow South Korea’s example of welcoming a visit by a US ballistic missile submarine, which would always carry dozens of nuclear warheads. But changes afoot in Washington mean Australia could soon be regularly hosting other types of nuclear-capable submarines—those that can deliver nuclear weapons even if the US neither confirms nor denies that any are aboard.

Largely overlooked in Australia, the US Congress has funded development of a nuclear-tipped cruise missile for use at sea, formally called SLCM-N, to become provisionally operational by 2034. Such nuclear cruise missiles have not been deployed on US Navy vessels since the early 1990s.

The new ones seem to be primarily earmarked for Virginia-class attack submarines—a type of boat that visits Australia regularly and will form part of the rotational force being established at the base HMAS Stirling in Western Australia later this decade as part of AUKUS.

Politics could still get in the way, but there is bipartisan support for SLCM-N in the US Congress and the Biden administration’s opposition has lessened. If Trump wins, its future should be secure. Elbridge Colby, who is widely tipped for a top national security role in a second Trump administration, is a fan.

Some might be inclined to shrug, as nuclear-capable bombers have been rotating through our airfields for decades, exploiting a caveat in the South Pacific Nuclear Free Zone treaty that bans the ‘stationing’ of nuclear weapons in Australia but not visits by US nuclear forces.

But the nuclear threats we face today, including China’s rapid missile buildup and sabre-rattling by Russia and North Korea, are more complicated than those we faced in the Cold War, when the treaty was drawn up against the backdrop of large anti-nuclear protests.

Washington is adjusting its posture to meet these evolving threats. The New York Times has reported that revisions to US nuclear strategy approved by Biden earlier this year focused more on countering China, although the White House has denied that any country was singled out.

Australia will have a greater say over changes to US nuclear posture if it does more to support extended deterrence than host such joint facilities as Pine Gap. But doing more will require public understanding and support, which the government must build.

Canberra’s first task is ensuring that disinformation about US nuclear weapons does not undermine AUKUS. The fact that the Royal Australian Navy will purchase Virginia-class submarines from the US Navy in the 2030s does not mean Australia is acquiring a nuclear weapons capability, as the new AUKUS treaty tabled in Parliament this month makes clear.

But the government cannot afford to bunker down behind defensive press lines. Ministers must make the case to the Australian public and the international community that the US nuclear umbrella, which relies on support from allies, helps make the world more stable and less prone to the proliferation of nuclear weapons.

Encouragingly, the AUSMIN statement, issued after Foreign Minister Penny Wong and Defence Minister Richard Marles met their US counterparts at the US Naval Academy earlier this month, complemented Washington’s ‘responsible transparency’ as a nuclear power and called on Beijing and Moscow to improve. It’s a start, but still far from the level of candour we need.

Behind the public rhetoric, Australian ministers, officials and military planners should already be sharing views about nuclear deterrence with their US counterparts through the dialogues and force posture initiatives that manage the alliance.

But coordination is also essential with other US allies, notably Japan and South Korea, if Australian voices are to be heard clearly in Washington.

At a practical level, Canberra and Washington need to thrash out how Australian sailors can continue to train on US attack submarines that might in future be nuclear-capable, which is vital for the success of AUKUS.

Longer term, the Australian Defence Force could even follow NATO’s example by integrating elements of its conventional forces into US nuclear planning and operations.

But treaty obligations prevent Australia storing US nuclear weapons on its soil, as takes place at some European airbases. NATO’s so-called nuclear sharing arrangements are really about the pooling of responsibilities and decision-making, which is also where Canberra should focus.

Australian interests are best served by contributing more actively to extended nuclear deterrence, including being open to hosting more US nuclear forces, without seeking nuclear weapons.

Ducking the issue and covering the debate with anodyne talking points will deter nobody.